Alvaro and Randall Both Feel Strongly About Global Warming

Alvaro and Randall both feel strongly about global warming.Alvaro believes that it is an imminent danger;Randall believes its exaggerated hype.Both have been invited to present their views to an audience of students who are majoring in the biological sciences.Alvaro arrives in jeans and a flannel shirt.He knows he isn't particularly attractive and he is at least twice the age of most of the students,but he hopes they will be able to relate to his dress style.Randall is only a few years older than the students;he arrives in a jacket and tie and has clearly taken care with his appearance.Based on this information alone,who are the students more likely to view as credible?

A) Alvaro,because they can relate to his style of dress.
B) Alvaro,because attractive,professional-looking people tend to be intimidating to average-looking people.
C) Randall,because he is attractive,dressed like a professional,and similar to the students in age.
D) Randall,because his name is more "American" than Alvaro's.